Young_Gun

So, when I take my car (06GT manual) out of gear and the idle falls, the idle is sometimes a bit unstable, fluctuating between 500 and 1000 rpms (I have the idle set at 750), but today I was sitting in a parking lot and it just started - oscillating. I looked at my RPM gauge and it was down to about 600 and shaky. I turned off my headlights to reduce alternator strain and they unsteadily climbed to 900-1000 and held there with 10-20 rpm fluctuations. It seemed to smoothe out a bit when I turned off my head unit. I haven't gotten the chance to drive it yet or put on the tuner.

I had to reattach my air intake the other day, and I re ran the tune.

I always let my car warm up for about 10 minutes before I go anywhere, with the headlights off but the radio on. I didn't notice any issue with that this morning.

Any ideas?

jpplaw

Hmm, since you re-installed the tune, it may need to relearn the idle parameters. Start her up, and without touching any pedals, just let it idle for about 10 minutes, then turn the A/C on and let it idle for a few more. See if it smoothes out after that.

Young_Gun

Even though I did the tune reinstall Sunday, and its probably spent 40 minutes at idle since then? (Like I said, I warm it up for 10 minutes before I leave every day)

I'll still try it and let you know.

nolimits

Seems like it's directly related to electrical draw, so have your battery/alternator tested.

bigblue95z

I'd suggest a re-flash of the tune and to also check the underside of the air intake to be sure that it is not folded under and nice and tight. Cleaning the throttle body is never a bad idea either if you're taking the intake off. I had some major idle issues that ended up being my tune. If your tune is a new one, not just a reflash, that is something that should be considered as well.

I'm assuming no CELs?

Nuke

Clean the TB.

moosestang

I've changed tunes over a dozen times and never had any unstable idle.

Norm Peterson

Probably wouldn't hurt to run through the throttle reset procedure.


Norm

busguy

I bought an '05 GT convertible 5 Speed a couple of months ago and love it! The only thing that I Hate with a capital H, is that when I take my foot off of the throttle, it takes 6-7 seconds for it to start slowing down! It's like the throttle is not coming down totally for that 6-7 seconds. I like to shift down and have the engine slow me down more than the brakes, but this is stupid. I brought the car to a very knowledgable shop the other day and he said that it's the nature of the beast! I don't believe it. I'm 68 and ran a bus maintenance shop for 25 years and never heard of this. Any opinions out there?

Nuke

Read post #6.